US2024219696A1PendingUtilityA1
Zoom lens and image pickup apparatus
Est. expiryJul 14, 2040(~14 yrs left)· nominal 20-yr term from priority
Inventors:Shinichiro Saito
G02B 15/1461G02B 13/0045G02B 13/006G02B 15/145113G02B 15/145121G02B 15/145129
76
PatentIndex Score
0
Cited by
0
References
0
Claims
Abstract
A zoom lens includes, in order from an object side to an image side, first, second and third lens units having positive, negative and positive refractive powers. The first lens unit moves during zooming. During zooming from a wide-angle end to a telephoto end, a distance between the first and second lens units widens, and a distance between the second and third lens units narrows. The first lens unit consists of three or less lenses. The second lens unit consists of, in order from the object side to the image side, a first single lens as a spherical lens having a negative refractive power, a cemented lens in which a lens having a negative refractive power and a lens having a positive refractive power are cemented, and a second single lens as a spherical lens having a negative refractive power. A predetermined condition is satisfied.
Claims
exact text as granted — not AI-modifiedWhat is claimed is:
1 . A zoom lens comprising four or more lens units including, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and a third lens unit having a positive refractive power,
wherein a distance between adjacent lens units varies during zooming from a wide-angle end to a telephoto end, wherein the first lens unit moves during zooming, wherein a distance between the first lens unit and the second lens unit at the telephoto end is wider than that at the wide-angle end, and a distance between the second lens unit and the third lens unit at the telephoto end is narrower than that at the wide-angle end, wherein a lens unit disposed closest to the image side in the zoom lens includes a single lens having a positive refractive power, wherein the first lens unit consists of three or less lenses, wherein the second lens unit consists of, in order from the object side to the image side, a first single lens as a spherical lens having a negative refractive power, a lens having a negative refractive power, a lens having a positive refractive power, and a second single lens as a spherical lens having a negative refractive power, and wherein following inequalities are satisfied:
4
0
≤
v
B
C
≤
80
4.
≤
❘
"\[LeftBracketingBar]"
f
1
/
f
2
❘
"\[RightBracketingBar]"
≤
80
3.1
≤
d
21
/
d
22
≤
1
0
.
0
where f 2 represents a focal length of the second lens unit, d 21 represents a distance on an optical axis between a lens surface on the image side of the first single lens and a lens surface on the object side of the lens having the negative refractive power, d 22 represents a distance on the optical axis between a lens surface on the image side of the lens having the positive refractive power and a lens surface on the object side of the second single lens, vBC represents an average value of Abbe numbers for a d-line, and f 1 represents a focal length of the first lens unit.
2 . The zoom lens according to claim 1 ,
wherein a following inequality is satisfied:
1.
≤
-
(
RA
2
+
RA
1
)
/
(
RA
2
-
RA
1
)
≤
1
0
.
0
where RA 1 represents a curvature radius of a lens surface on the object side of the first single lens, and RA 2 represents a curvature radius of the lens surface on the image side of the first single lens.
3 . The zoom lens according to claim 1 ,
wherein a following inequality is satisfied:
-
2
.
0
≤
(
RC
1
+
RB
2
)
/
(
RC
1
-
RB
2
)
≤
1.
where RB 2 represents a curvature radius of the lens surface on the image side of the lens having the negative refractive power, and RC 1 represents a curvature radius of the lens surface on the object side of the second single lens.
4 . The zoom lens according to claim 1 ,
wherein a following inequality is satisfied:
0
.6
≤
❘
"\[LeftBracketingBar]"
RBm
/
f
2
❘
"\[RightBracketingBar]"
≤
3.
where RBm represents a curvature radius of a cemented surface of the cemented lens.
5 . The zoom lens according to claim 1 ,
wherein following inequalities are satisfied:
1.51
≤
nBC
≤
1.85
where, for materials of the lens having the negative refractive power and the second single lens, nBC represents an average value of refractive indexes for the d-line.
6 . The zoom lens according to claim 1 ,
wherein a following inequality is satisfied:
4
.0
≤
❘
"\[RightBracketingBar]"
f
1
/
f
2
❘
"\[RightBracketingBar]"
≤
8.
where f 1 represents a focal length of the first lens unit.
7 . The zoom lens according to claim 1 ,
wherein a following inequality is satisfied:
3.5
≤
❘
"\[LeftBracketingBar]"
f
1
/
fw
❘
"\[RightBracketingBar]"
≤
10
.
0
where fw represents a focal length of the zoom lens at the wide-angle end.
8 . The zoom lens according to claim 1 ,
wherein a following inequality is satisfied:
0.2
≤
❘
"\[LeftBracketingBar]"
f
3
/
ft
❘
"\[RightBracketingBar]"
≤
0.
6
where f 3 represents a focal length of the third lens unit, and ft represents a focal length of the zoom lens at the telephoto end.
9 . The zoom lens according to claim 1 ,
wherein a following inequality is satisfied:
0
.
3
≤
V
<
¯
1.
where V represents a third-order aberration coefficient of a distortion that occurs in the zoom lens at the wide-angle end.
10 . The zoom lens according to claim 1 ,
wherein a following inequality is satisfied:
-
15.
≤
d
min
≤
-
4.4
where dmin represents a percentage of distortion at a maximum image height, the distortion occurring in the zoom lens at the wide-angle end.
11 . The zoom lens according to claim 1 ,
wherein the zoom lens consists of, in order from the object side to the image side, the first, second and third lens units, a fourth lens unit having a negative refractive power, and a fifth lens unit having a positive refractive power.
12 . The zoom lens according to claim 1 ,
wherein the zoom lens consists of, in order from the object side to the image side, the first, second and third lens units, a fourth lens unit having a negative refractive power, a fifth lens unit having a positive refractive power, and a sixth lens unit having a negative refractive power.
13 . The zoom lens according to claim 1 ,
wherein the zoom lens consists of, in order from the object side to the image side, the first, second and third lens units, a fourth lens unit having a negative refractive power, a fifth lens unit having a positive refractive power, a sixth lens unit having a negative refractive power, and a seventh lens unit having a negative refractive power.
14 . An apparatus comprising:
a zoom lens; and
a sensor configured to receive an optical image formed by the zoom lens,
wherein the zoom lens includes four or more lens units including, in order from an object side to an image side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, and a third lens unit having a positive refractive power,
wherein a distance between adjacent lens units varies during zooming from a wide-angle end to a telephoto end,
wherein the first lens unit moves during zooming,
wherein a distance between the first lens unit and the second lens unit at the telephoto end is wider than that at the wide-angle end, and a distance between the second lens unit and the third lens unit at the telephoto end is narrower than that at the wide-angle end,
wherein a lens unit disposed closest to the image side in the zoom lens includes a single lens having a positive refractive power,
wherein the first lens unit consists of three or less lenses,
wherein the second lens unit consists of, in order from the object side to the image side, a first single lens as a spherical lens having a negative refractive power, a lens having a negative refractive power, a lens having a positive refractive power, and a second single lens as a spherical lens having a negative refractive power, and
wherein following inequalities are satisfied:
4
0
≤
vBC
≤
80
4.
≤
❘
"\[LeftBracketingBar]"
f
1
/
f
2
❘
"\[RightBracketingBar]"
≤
8.
3.1
≤
d
21
/
d
22
≤
1
0
.
0
where f 2 represents a focal length of the second lens unit, d 21 represents a distance on an optical axis between a lens surface on the image side of the first single lens and a lens surface on the object side of the lens having the negative refractive power, d 22 represents a distance on the optical axis between a lens surface on the image side of the lens having the positive refractive power and a lens surface on the object side of the second single lens, vBC represents an average value of Abbe numbers for a d-line, and f 1 represents a focal length of the first lens unit.
15 . The apparatus according to claim 14 ,
wherein a following inequality is satisfied:
1.
0
≤
-
(
RA
2
+
RA
1
)
/
(
RA
2
-
RA
1
)
≤
1
0
.
0
where RA 1 represents a curvature radius of a lens surface on the object side of the first single lens, and RA 2 represents a curvature radius of the lens surface on the image side of the first single lens.
16 . The apparatus lens according to claim 14 ,
wherein a following inequality is satisfied:
-
2
.
0
≤
(
RC
1
+
RB
2
)
/
(
RC
1
-
RB
2
)
≤
1.
where RB 2 represents a curvature radius of the lens surface on the image side of the lens having the negative refractive power, and RC 1 represents a curvature radius of the lens surface on the object side of the second single lens.
17 . The apparatus lens according to claim 14 ,
wherein a following inequality is satisfied:
0
.6
≤
❘
"\[LeftBracketingBar]"
RBm
/
f
2
❘
"\[RightBracketingBar]"
≤
3.
where RBm represents a curvature radius of a cemented surface of the cemented lens.
18 . The apparatus lens according to claim 14 ,
wherein following inequalities are satisfied:
1.51
≤
nBC
≤
1.85
where, for materials of the lens having the negative refractive power and the second single lens, nBC represents an average value of refractive indexes for the d-line.
19 . The apparatus according to claim 14 ,
wherein a following inequality is satisfied:
3.5
≤
❘
"\[LeftBracketingBar]"
f
1
/
fw
❘
"\[RightBracketingBar]"
≤
10
.
0
where fw represents a focal length of the zoom lens at the wide-angle end.Join the waitlist — get patent alerts
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